Although Tropical Storm Iselle moved beyond the Big Island and the state, power outages caused by the powerful cyclone remain a significant problem for thousands.

Hawaii Electric Light Co. said Saturday that power, which initially had been knocked out to about a third of the island’s customers, has been restored to all but 9,200 customers, who have been warned by the utility not to expect their lights on soon.

“Customers still without power should expect extended outages, which could last into next week and in some cases, particularly the Puna area, much longer,” HELCO said in a written statement.

Most of the affected residents are in lower Puna, including Hawaiian Paradise Park, Orchidland Estates, Leilani Estates, Nanawale, Kapoho, Kalapana, Hawaiian Beaches, Hawaiian Shores and Waipunahina. In addition, there are outages affecting pockets of customers in areas from Hamakua through Volcano.

“HELCO has been working really hard to restore power,” Hawaii County Civil Defense Administrator Darryl Oliveira said early Saturday evening. “When you consider only 48 hours after the event, what HELCO has been doing to restore power for initially more than 30,000 customers to down to 9,000 customers, it’s been a huge effort on their part.”

HELCO said its crews are focusing on repairing damage to the island’s transmission system, described as “the backbone of the electric grid and … essential to providing service across the island.” The utility said much of the damage is in remote areas and in many cases, crews have to cut their way through fallen trees to provide access for vehicles, equipment and personnel.

Police said in a Saturday message there had been reports of residents in lower Puna confronting HELCO work crews attempting to restore power and are asking residents to remain calm and be patient.

“It’s unconfirmed reports, nothing substantiated,” Deputy Police Chief Paul Ferreira said. “To just be on the safe side, we just want to let the community know that HELCO is trying to get out to all the isolated areas. If people get frustrated and get into (workers’) faces, it’s not going to help anything.”

Ferreira said the reports are of verbal confrontations, nothing physical.

The Hawaii Red Cross reported about 90 people stayed overnight Friday at its evacuation shelter at Keaau High School, the final shelter remaining open Friday. That shelter was closed Saturday, Oliveira said.

“We have opened another shelter at Aunty Sally’s Luau House (in Hilo),” he said. “We’ve opened it for people who have been displaced by storm damage. Part of it is there are shower facilities right next door at the (Sparky Kawamoto Swim Stadium) that might be available.

“At the shelter, people will need to bring their own provisions: bedding, food, things like that.”

The Pahoa Community Center and the village’s county pool also will remain open 24 hours for residents to take showers and charge cellphones. The pool is not open for swimming.

Oliveira said that under the circumstances, most of the community has been patient and thanked them for it.

“It’s very frustrating for people who are going through this and suffering from the impacts of the storm,” he said. “We’re trying to respond to their needs, ice, water and tarps … as well as the crews who are trying to clear debris. They’re working very hard. The county, National Guard, even local residents have been working on the cleanup.”

The state Department of Education will resume regular public school schedules and student activities Monday with the exception of Waiakea High, which will reopen to students Tuesday.

Kamehameha Schools reported that all of its sites except for preschool facilities in Keaau and Pahoa, which are without power, will reopen Monday, pending any changes with the track of Hurricane Julio.

All state courthouses and judiciary offices will also reopen Monday. If weather conditions change, further announcements will be made.

The Coast Guard reopened all ports in the state following the passing of Iselle.

The Coast Guard continues to monitor Hurricane Julio and heavy weather conditions for each port will be updated as information becomes available.

Hawaii Volcanoes National Park partially reopened Saturday, with some closures in effect as park officials assess damage and remove fallen trees and other debris from roadways.

The Department of Land and Natural Resources reported that Lava Tree State Monument and MacKenzie State Recreation Area in Puna are closed, as are all areas managed by the Division of Forestry and Wildlife, including forest reserves, wildlife sanctuaries, natural area reserves, forest hiking trails and game management areas, until further notice.

All other state parks are open, as are the state’s small boat harbors.